This document discusses models of farms and their application for sustainable intensification of agriculture. It summarizes that household modeling can help understand household vulnerabilities and priorities through surveys, interviews and discussion groups. Models can also help increase preparedness and resilience through strategic scenario analyses using downscaled climate models and improved risk management with forecasting tools. Participatory whole farm modeling can help diagnose current production systems, explain farmer decisions, and explore new management systems that increase resilience and profitability under different future scenarios. Models represent complex systems through various approaches like scenarios and sensitivity analyses, stochastic environments, and evolutionary approaches. The document questions how "optimum" a solution needs to be, noting that farmer decisions are usually good enough even if not perfect. It discusses